I recently fitted a new cat section to my 1.2 16v clio but the clamp I got in the clamp which connects the cat section to the middle section never sealed and the exhaust is blowing. I have noticed that when the car is idling there is an intemittent pop which is also present whenI back of the throttle. Is Iit possible this is caused by the blowing exhaust? Any help or suggestions greatly appreciated.